/// <summary>
/// Converts the specified BitmapPixels to grayscale.
/// </summary>
/// <param name="pixels">The BitmapPixels to convert.</param>
public static void MakeGrayscal(BitmapPixels pixels)
{
unsafe
{
RGBAColor *color_ps = pixels.Pointer;
byte new_pixel;
for (int pixel = 0; pixel < pixels.Height * pixels.Width; pixel++, color_ps++)
{
new_pixel = (byte)(color_ps->R * 0.2126 + color_ps->G * 0.7152 + color_ps->B * 0.0722);
*color_ps = new RGBAColor(new_pixel, new_pixel, new_pixel, color_ps->A); //set the new pixel using the existing alpha component
}
}
}
private async void FileOpenMenuItem_Click(object sender, EventArgs e)
{
if (OpenImageDialog.ShowDialog() == DialogResult.OK)
{
using (var originalBitmap = Bitmap.FromFile(OpenImageDialog.FileName) as Bitmap)
{
OriginalImage.Image = originalBitmap.Clone() as Bitmap;
Stopwatch timer = new Stopwatch();
BitmapPixelsGrayscaleImage.Image = await Task.Run(() =>
{
timer.Start();
Bitmap grayscaleBitmap = originalBitmap.Clone() as Bitmap;
using (BitmapPixels grayscaleBitmapPixels = new BitmapPixels(grayscaleBitmap))
{
grayscaleBitmapPixels.Lock();
MakeGrayscal(grayscaleBitmapPixels);
timer.Stop();
return(grayscaleBitmap);
}
});
BitmapPixelsConvertTimeLabel.Text = $"{timer.ElapsedMilliseconds} milliseconds";
timer.Reset();
SetPixelsGrayscaleImage.Image = await Task.Run(() =>
{
timer.Start();
Bitmap grayscaleBitmap = originalBitmap.Clone() as Bitmap;
MakeGrayscal(grayscaleBitmap);
timer.Stop();
return(grayscaleBitmap);
});
SetPixelConvertTimeLabel.Text = $"{timer.ElapsedMilliseconds} milliseconds";
}
}
}
/// <summary>
/// 読み込み済み画素値から2点を結ぶ線上の画素値を返します
/// </summary>
/// <param name="point1XRatio">開始点Xの割合(0~1)</param>
/// <param name="point1YRatio">開始点Yの割合(0~1)</param>
/// <param name="point2XRatio">終了点Xの割合(0~1)</param>
/// <param name="point2YRatio">終了点Yの割合(0~1)</param>
/// <returns>RGBの画素値配列(8bit)</returns>
public ReadOnlySpan <(byte R, byte G, byte B)> GetRgbLineLevels(
double point1XRatio, double point1YRatio, double point2XRatio, double point2YRatio)
{
using (var bitmapPixels = new BitmapPixels(BitmapSource))
{
try
{
int limit(int v, int max) => (v <= 0) ? 0 : ((v >= max) ? max : v);
int widthMax = bitmapPixels.Width - 1;
int heightMax = bitmapPixels.Height - 1;
int p1x = limit((int)(point1XRatio * widthMax), widthMax);
int p1y = limit((int)(point1YRatio * heightMax), heightMax);
int p2x = limit((int)(point2XRatio * widthMax), widthMax);
int p2y = limit((int)(point2YRatio * heightMax), heightMax);
int diffX = p2x - p1x;
int diffY = p2y - p1y;
double distance = Math.Sqrt(diffX * diffX + diffY * diffY);
var rgbs = new (byte R, byte G, byte B)[(int)distance];